12-02-2025
NAU researcher outlines new risks of warming, warns of faltering US science leadership
Accelerated warming in the Arctic will lead to a breakdown of ecosystems and infrastructure that will have damaging consequences cascading all the way to Arizona, according to new research published last week in the prestigious peer-reviewed journal Science.
At the same time, a political retreat from domestic efforts to slow climate change and support international research collaborations will lead to a breakdown of many privileges Americans take for granted, said an author of that paper who is based at Northern Arizona University.
"I personally am a carbon cycle scientist because I want to help make a difference," said Ted Schuur, a professor of ecosystem ecology at NAU who collaborated with researchers from Canada, Germany and Denmark on the newly published review of climate impacts at 2.7 degrees Celsius of warming above preindustrial levels.
"If we care about our kids and grandkids and future generations, this doubling down on fossil fuel use that we know is the wrong direction is not a good path," he told The Arizona Republic. "Mixing science and politics together, which I guess is always the case with climate policy, feels even more heightened in the past few weeks."
Schuur was referring to a flurry of anti-science, anti-climate actions President Donald Trump has taken during his first weeks back in office that include withdrawing the United States from the international Paris Agreement to reduce climate-warming fossil fuel emissions; issuing orders to accelerate oil drilling and reverse progress on domestic clean energy development instead; and broadly interrupting funding for domestic and international research efforts.
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The paper the team including Schuur published last week was submitted for peer review before Trump took office, but has since taken on new significance.
It evaluates expected changes to ice sheets and permafrost in Greenland and other Arctic ecosystems at 1.5 and at 2.7 degrees Celsius of average global warming above preindustrial levels and contrasts how those changes would influence climatic shifts and landscape habitability across the planet.
In 2015, the historic Paris Agreement established international pledges to keep warming below 1.5 degrees, which scientists had determined would be necessary to avert major undesirable impacts of a destabilized climate. That increase is compared to a baseline average temperature on Earth between 1850 and 1900 before humans were burning fossil fuels for energy at large scales, releasing greenhouse gas byproducts into the atmosphere that trap heat from the sun and result in higher temperatures and more chaotic storms.
The first 12-month breach of 1.5 degrees occurred during the warmth-boosting El Niño of February 2023 to January 2024, a period that also saw an uptick in extreme weather events. Just last week, James Hanson, the climate scientist who first warned Congress about an overheated atmosphere in 1988, said he expects humans will also fail to meet the next target benchmark of 2 degrees, given actual warming that has exceeded past projections once deemed "alarmist."
The most recent scientific consensus, with rates of ongoing global fossil fuel use, is that Earth will reach 2.7 degrees C of average warming by 2100, leading to dangerous climate impacts like supercharged heat waves and storms.
In response, Schuur and his international team of co-authors worked together this summer to evaluate the published literature on expected impacts at the 1.5- and 2.7-degree goalposts on Arctic ecosystems and beyond.
By the time the report was published, in the midst of Trump pulling the U.S. out of the international Paris Agreement to reduce emissions and rolling back clean energy funding to do the same, the urgency of its findings had only increased.
"Part of the story is we weren't aiming at 2.7, but the world pledged to reduce a certain amount and now (scientists found) that already takes us to 2.7," Schuur said. "But everything I'm talking about was (based on) what we had been doing up until January 20. So, obviously, we've taken a hard turn."
A planet with average temperatures 2.7 degrees Celsius higher than during preindustrial times would render Arctic landscapes "transformed beyond contemporary recognition," the researchers including NAU's Schuur concluded in last week's published paper.
The Arctic Ocean would be ice-free for most of the summer, disrupting marine ecosystem functioning, fisheries, human ground transportation via snowmobiles and the ability of animals like polar bears to hunt for food, the scientists found. That extra meltwater would result in around 10 feet of sea level rise, leading to larger waves, more coastal erosion and damage to built infrastructure on land and at sea.
The last time the Arctic Ocean was ice-free was 130,000 years ago, due to natural, background climate fluctuations that have remained relatively stable over human history until now.
When the Arctic's normally frozen, white surface melts, it also exposes the darker permafrost below, which then reflects less heat from the sun and kicks off a two-fold acceleration of climatic warming, Schuur told The Republic.
"As we lose ice and snow, we change the reflectivity of the planet, and so the planet warms up faster from the disappearing cryosphere," he said. The exposed permafrost then accelerates further melting, runoff and sea level rise while releasing more warming carbon gasses into the atmosphere that had previously been stored beneath the ice.
At 1.5 degrees of average warming, some of that ice loss would build back during colder years. But at 2.7 degrees, several studies the scientists reviewed concluded it would be irreversible. The expected loss of this freeze and thaw cycle by 2100 would, the scientists found, permanently disrupt the normal functioning of Arctic ecosystems and wildlife food chains, the reliability of the marine fisheries industry and the stability of coastal infrastructure, including the seaside homes of Indigenous communities who have contributed little to the causes of climate change.
And those changes would not be confined to the northern polar region.
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Arizona is changing in parallel with the Arctic, Schuur told The Republic, as evidenced by recent record high temperatures and shifting weather patterns that affect the water cycle and drought. An explosion of greenhouse gases coming out of the Arctic will warm and desiccate the climate in Arizona, too, pushing the limits of its habitability.
"The question is, why in Arizona do we care about the changing Arctic?" Schuur asked. "One answer is that what's changing in the Arctic is directly linked to global changes, and so the same kind of changes are happening here with these heat temperature records in Phoenix. What's that going to look like in 10 or 20 years? It could be pushing the limits of even wanting to live here."
Just as changes to the climate and landscapes in the Arctic send ripple effects all over the globe, the state of scientific collaboration's consequences are borderless.
Schuur told The Republic he has already been directly affected by Trump's orders to pause scientific work funded by federal grants and to restrict scientists working for federal agencies from communicating with collaborators at institutions outside the government. He said this dismantling of American leadership in science immediately influenced what he's able to do, and will surely cause the United States to lose ground in the global research dominance it has enjoyed for generations.
"This nation has led the way for 50 or 70 years, and the things that are happening right now at the federal level really look to crimp that down," Schuur said. "That has the potential of handing over advantages of science to other nations. I think we're just gonna hurt our own competitiveness and our own knowledge."
Read our climate series: The latest from Joan Meiners at azcentral: climate coverage from Arizona and the Southwest
Even if Trump's actions to stall the flow of research money don't withstand the legal challenges already filed against them, the chaos caused at the National Science Foundation and the National Institutes of Health by disrupting grant funding to projects that have been designed, planned and, in some cases, are already underway will leave a mark. Long-term research like Schuur's ongoing work in the Arctic is timed to specific seasonal windows and often requires months of planning to arrange travel and permits after funding is secured.
"This nation, I think, became wealthy, powerful and important because we had a science-based, open, transparent way to learn and that is really what seems to be under attack right now," he said. "If we cut those ties, even within our own nation, which is happening now, or internationally, we just suffer as a result, as humans, in terms of understanding what's going on and trying to forecast where we're going to end up in the future."
There is a precedent mentioned in last week's Science paper for what gets lost when international flows of data and research connections are interrupted. After the Russian invasion of Ukraine, the established ecosystem monitoring network made up of a small group of scientists across the world who study the Arctic was diminished, cutting off access to 50% of the available information on carbon flux monitoring that was being collected at sites controlled by the Russian Federation. The related militarization of the Arctic region and science in general is also resulting in more damage to those ecosystems and disruption to their long-term management and study, the paper concluded.
"As Arctic researchers, we're working in a remote area where we always wish we had more data," Schuur said. "But the best we can do is collaborate with scientists around the world that are making similar observations."
One more obvious but perhaps seldom-noticed aspect of the new research paper Schuur wrote with colleagues from Denmark, Germany and Canada may be at stake: It's in English. That is a direct result of the United States dominating the international science research scene for generations, Schuur said, by funding and sending American scientists to collaborative projects around the world.
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But with China and India far outpacing the United States in numbers of STEM graduates in recent years, according to data compiled by Georgetown University's Center for Security and Emerging Technology in 2023 and by Statista in 2017, all that could change.
"I think we enjoy a lot of things being Americans that we take for granted, that have happened because we're a large nation that has led the way," Schuur said. "If you think about the English language, transparent science, the open internet, or the use of the dollar for different nations to run their economies, it doesn't have to be like that," Schuur said.
"It's that way because we led the way," he said. "We provided a model that was open and let people into it. But that can be broken. I think we have a real risk of falling behind and not really realizing it until five or 10 years has passed."
Joan Meiners is the climate news and storytelling reporter at The Arizona Republic and Her award-winning work has also appeared in Discover Magazine, National Geographic, ProPublica and the Washington Post Magazine. Before becoming a journalist, she completed a doctorate in ecology. Follow Joan on Twitter at @beecycles, on Bluesky @ or email her at
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This article originally appeared on Arizona Republic: Researchers find new warming threats, warn about attacks on science
